CPESC Inspection Procedures 3 — Questions and Answers
Question 1: What does the term 'stabilization' mean in the context of a final construction site inspection?
- All grading activities have ceased permanently
- All exposed soil areas are covered with vegetation or non-erodible material meeting permit thresholds (Correct answer)
- The site has been sold to the new property owner
- All temporary BMPs have been removed from the site
Correct answer: All exposed soil areas are covered with vegetation or non-erodible material meeting permit thresholds
Final stabilization requires that exposed soil be covered with uniform vegetative cover (typically 70–80% density) or permanent non-erodible materials.
Question 2: During an inspection, an inlet protection device is found to be bypassed by stormwater flowing around its edges. What is the BEST corrective measure?
- Remove and replace the device with a larger model
- Regrade the area around the device to direct flow through it and repair or extend the device (Correct answer)
- Install a second inlet protection device downstream
- Place sandbags at the inlet opening
Correct answer: Regrade the area around the device to direct flow through it and repair or extend the device
Regrading and repairing the device to eliminate bypass flow addresses the root cause of the failure rather than simply adding redundancy.
Question 3: Which of the following conditions at a construction entrance / exit would indicate a BMP failure requiring correction?
- Rock aggregate is 2 inches below the design depth
- Vehicles are depositing mud and sediment onto the public roadway (Correct answer)
- The entrance width is 2 feet narrower than the design width
- Grass is beginning to grow between aggregate stones
Correct answer: Vehicles are depositing mud and sediment onto the public roadway
Tracking of sediment onto public roads is the primary sign that a construction entrance is failing its purpose and requires immediate maintenance.
Question 4: An inspector notices that a temporary diversion dike has been overtopped and eroded. Which hazard does this MOST directly create?
- Increased dust generation on the site
- Uncontrolled stormwater runoff bypassing sediment controls and reaching waterways (Correct answer)
- Instability of adjacent permanent structures
- Reduced access for construction equipment
Correct answer: Uncontrolled stormwater runoff bypassing sediment controls and reaching waterways
An overtopped diversion dike allows runoff to bypass the planned BMP system and discharge sediment-laden water directly to receiving waters.
Question 5: Under what condition may routine weekly inspections be reduced to once every 14 calendar days under many NPDES CGPs?
- When the site is located more than 1 mile from a water body
- When the site has been temporarily stabilized and no earth disturbance is occurring (Correct answer)
- When the project owner provides a written waiver request
- When fewer than 5 acres are disturbed at one time
Correct answer: When the site has been temporarily stabilized and no earth disturbance is occurring
Most CGPs allow reduced inspection frequency when areas are temporarily stabilized and no active earth disturbance is occurring in those areas.
Question 6: When evaluating a check dam in a drainage swale, which measurement is most important for assessing sediment storage performance?
- The height of the check dam above the channel bed
- The depth of sediment accumulated upstream of the structure relative to its spillway elevation (Correct answer)
- The velocity of flow passing over the spillway
- The distance between consecutive check dams
Correct answer: The depth of sediment accumulated upstream of the structure relative to its spillway elevation
Sediment depth relative to spillway elevation determines when cleanout is needed to maintain the structure's storage and filtering effectiveness.
Question 7: A CPESC inspector finds that a subcontractor has begun grading in an area not covered by the current SWPPP. What is the correct response?
- Allow work to continue while updating the SWPPP retroactively
- Direct the subcontractor to stop work in that area and update the SWPPP before resuming (Correct answer)
- Add a temporary silt fence around the area and continue grading
- Document the deficiency and notify the owner at the end of the week
Correct answer: Direct the subcontractor to stop work in that area and update the SWPPP before resuming
Work cannot proceed in areas outside the SWPPP coverage; the plan must be amended and BMPs installed before earth disturbance continues.
CPESC Inspection Procedures 3
What does the term 'stabilization' mean in the context of a final construction site inspection?